NASA Baffled by Unexplained Force Acting on Space Probes

“There is something very strange going on with spacecraft motions. We have no convincing
explanation for either the Pioneer anomaly or the flyby anomaly.” The fact this effect seems most evident with flybys most asymmetrical with respect to Earth’s equator “suggests that the anomaly is related to Earth’s rotation,” Anderson said.

One possible explanation might be that solar system is accelerating through space.